Descartes

Edo ergo caco. Caco ergo sum! [/shitty joke]

Serious now. Descartes was also trying to solve solipsism, but through a different method: he claims at least some sort of knowledge ("I doubt thus I think; I think thus I am"), and then tries to use it as a foundation for more knowledge.

What I'm doing is different. I'm conceding that even radical scepticism, a step further than solipsism, might be actually correct, and that true knowledge is unobtainable (solipsism still claims that you can know that yourself exist). However, that "we'll never know it" is pointless, even if potentially true, because it lacks any sort of practical consequence. I learned this from Cicero (it's how he handles, for example, the definition of what would be a "good man").

Note that this matter is actually relevant in this topic. We're dealing with black box systems, that some claim to be conscious; sure, they do it through insane troll logic, but the claim could be true, and we would have no way to know it. However, for practical matters: they don't behave as conscious systems, why would we treat them as such?